More than 5000 homeowners in Whakatū Nelson, will learn this week if their properties could be susceptible to liquefaction or fault rupture in an earthquake.
File photo: Nelson City Photo: RNZ / Tracy Neal
This new hazard information will be added to new Land Information Memorandum notations on their property files.
The information comes from a series of independent, region-wide assessments of liquefaction and fault rupture commissioned by the Nelson City Council as part of its responsibility to investigate potential risk from natural hazards.
Council environmental management group manager Clare Barton said it has a responsibility to keep residents informed about natural hazards.
"As a council, in addition to our legal and regulatory obligations, we feel it's important property owners are kept up to date and informed about any potential hazard information that may affect their property, particularly people that are considering developing, purchasing, modifying or changing the use of properties in some way."
Letters will be sent to owners of properties that do not have an existing LIM notation relating to liquefaction or fault rupture. Where a LIM notation already exists, it will be updated to reflect the recent information and property owners will not receive a letter.
The Nelson region contains eight known fault lines - Flaxmore, Waimea, Eighty-Eight, Jenkins, Whangamoa, Bishopdale, Grampian and Hira faults.
The updated reports and maps showed areas where faults could potentially deform or rupture the ground surface.
They also updated information on areas prone to liquefaction - the process where soil behaves more like a liquid than a solid after an earthquake.
Site-specific assessments may need to be undertaken by a technical expert to assess the specific fault hazard at any individual site or property.
A small number of households will also receive a letter to inform them their property is within the contamination footprint of the old Atawhai landfill site.
The affected area is bounded by Queen Elizabeth II Drive to the northwest, Atawhai Drive to the east, Weka Street to the south and Sovereign Street to the west.
Council has carried out regular monitoring in this area, including for gas emissions and groundwater contamination.
The Site Investigation Report held by Council includes some testing results for specific test locations - some of which are on private properties.
Not all properties within the contamination footprint of the old landfill will have contaminated soil, and property owners can carry out their own site-specific assessment to determine whether their land has been affected.
Residents can view the full reports and maps at the Nelson City Council website.